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NASA funding project for nuclear-powered travel to Mars

NASA Seeks Nuclear Power for Mars After a half-century hiatus, the agency is reviving its reactor development with a test later this summer, Scientific American By Irene Klotz, SPACE.com on June 30, 2017, As NASA makes plans to one day send humans to Mars, one of the key technical gaps the agency is working to fill is how to provide enough power on the Red Planet’s surface for fuel production, habitats and other equipment. One option: small nuclear fission reactors, which work by splitting uranium atoms to generate heat, which is then converted into electric power.

NASA’s technology development branch has been funding a project called Kilopower for three years, with the aim of demonstrating the system at the Nevada National Security Site near Las Vegas. Testing is due to start in September and end in January 2018.

The last time NASA tested a fission reactor was during the 1960s’ Systems for Nuclear Auxiliary Power, or SNAP, program, which developed two types of nuclear power systems. The first system — radioisotope thermoelectric generators, or RTGs — taps heat released from the natural decay of a radioactive element, such as plutonium. RTGs have powered dozens of space probes over the years, including the Curiosity rover currently exploring Mars. [Nuclear Generators Power NASA Deep Space Probes (Infographic)]

The second technology developed under SNAP was an atom-splitting fission reactor. SNAP-10A was the first — and so far, only — U.S. nuclear power plant to operate in space. Launched on April 3, 1965, SNAP-10A operated for 43 days, producing 500 watts of electrical power, before an unrelated equipment failure ended the demonstration. The spacecraft remains in Earth orbit.

Russia has been far more active developing and flying spacecraft powered by small fission reactors, including 30 Radar Ocean Reconnaissance Satellites, or RORSAT, which flew between 1967 and 1988, and higher-powered TOPAZ systems. TOPAZ is an acronym for Thermionic Experiment with Conversion in Active Zone.

NASA engineers figure human expeditions to Mars will require a system capable of generating about 40 kilowatts of power, which is about what is needed for “about eight houses on Earth,” according to the agency. Curiosity’s RTG was designed to supply about 125 watts — less energy than what is needed to power a microwave oven — though power levels fall as the radioactive plutonium decays. [How Will a Human Mars Base Work? NASA’s Vision in Images]

Solar power is another option, but that would restrict power generation to regions that are exposed to enough sunlight to charge batteries. Inside the moon’s Shackleton Crater, for example — a prime candidate for lunar sorties due to its water resources — it is completely dark. The sunniest spots on Mars receive only about one-third the amount of sunlight as Earth does.

“If you want to land anywhere, surface fission power is a key strategy for that,” Michelle Rucker, an engineer at NASA’s Johnson Space Center in Houston, said during a presentation in December to NASA’s Future In-Space Operations working group.

Fission reactors also can continue working in adverse weather conditions, such as Mars’ ubiquitous dust storms. ……

Partners in the Kilopower project include NASA’s Glenn Research Center, the Department of Energy, Los Alamos National Lab and the Y12 National Security Complex, which supplies the reactor’s uranium.